Heat generator of the smoke-tube type

ABSTRACT

A heat generator of the smoke-tube type which includes a furnace and a plurality of smoke tubes. Both the furnace and the tubes are made of a single metal sheet which is folded. The tubes are arranged circularly around the furnace or a part of the furnace. The shape of the tubes is such that there is communication between the tubes and the furnace for reversing the flow of the smoke. The tubes are of a constant or of a variable cross section.

[ 1 June 27, 1972 United States Patent Joannes S T. N E Mm GP S m m m N U 6 U E m M S E H T F O R O T A H mm Gw T E mm H T M U Dicks [72] Inventor: Giuseppe Joannes,Rivoli,lta1y [73] Assignee: Gruppo Finanziario Termico Fin-Term S.p.A, Turin, Italy 9929 5822 9899 1111 WWW 1 11 0870 3251 7854 043 2 1 Primary Examiner-Kenneth W. Sprague AnorneySughrue, Rothwell, Mion, Zinn & Macpeak W6 W0 4 0 N L D. P p FA 1.] 21 22 [.1

ABSTRACT Foreign Application Priority Data A heat generator of the smoke-tube type which includes a furnace and a plurality of smoke tubes. Both the furnace and the tubes are made of a single metal sheet which is folded. The tubes are arranged circularly around the furnace or a part of the furnace. The shape of the tubes is such that there is communication between the tubes and the furnace for reversing the flow of the smoke. The tubes are of a constant or of a variable cross section.

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4 Claims, 10 Drawing Figures 1 HEAT GENERATOR OF THE SMOKE-TUBE TYPE BACKGROUND OF THE INVENTION expensive structure and need special seal devices in the case.

of combustion under pressure.

SUMMARY OF THE INVENTION It is an object of the present invention to obviate the above disadvantages by providing a heat generator of a very simple and sturdy design and which makes it possible to eliminate the use of calandria plates at the places where the flow of the smoke is reversed.

Another object of the invention is to provide a heat generator of the above type that is usable with minor changes for any kind of liquid, solid or gaseous fuel and for use either for normal combustion or combustion under pressure.

The main feature of the heat generator of the present invention consists in the fact that the furnace and the smoke tubes are made from a single metal sheet so folded in the longitudinal direction as to define both the combustion chamber or the furnace and the smoke'tub'es circularly disposed around the furnace.

According to another feature of the invention, the portions of the sheet which form the smoke tubes are so deformed at one end as to obtain communication between the furnace and such tubes in order to reverse the flow of the smoke.

BRIEF DESCRIPTION OF THE DRAWINGS Other features and advantages of the invention will become apparent from the following detailed description, with reference to the accompanying drawings, which are provided byway of non-limiting example and in which FIG. I is a front view diagram of a unit comprising a furnace and a plurality of smoke tubes which are parts of a heat generator according to the invention; I

FIGS. 2 and 3 show two variations of the embodiment of FIG. 1;

FIG. 4 is an axial section along the line IV-IV of FIG. 1;

FIG. 5 is a front view of a unit analogous with that of FIG. I, in which there are radial connections between the furnace and the smoke tubes;

FIG. 6 is an axial section along line VI-VI of FIG. 5;

FIG. 7 is a detail on enlarged scale of a generator of the type illustrated in FIG. 1, made according to a variation of said figure;

FIG. 8 is a side view of the detail shown by FIG. 7, and

FIGS. 9 and 10 are two diagrammatical sections of two different types of heat generator which use the units illustrated in the preceding figures.

DESCRIPTION OF THE PREFERRED EMBODIMENT With reference to FIGS. 1, 2 and 3, by 1, 14, lb is indicated a single sheet metal element which by being folded provides the furnace A and a plurality of smoke tubes B disposed circularly around the furnace in some or other pattern.

Such unit is obtained by folding the sheet 1, 1a, lb so as to make a number of flat strips which together define a furnace and a number of tubes 3, 3a, 3b of some or other shape separated from the furnace by means of longitudinal necks 4, 4a, 4b.

The tubes can be arranged in any pattern on the whole circumference of the furnace or on a part thereof and can be of any shape, as shown by FIGS. 1, 2 and 3. Also the furnace can be of any geometrical cross section.

According to a variation shown in FIGS. 5 and 6, at one end of the unit so made the outer tubes 3 have their end parts 5 deformed each into a funnel so as to provide communication in radial direction of chamber A of the furnace with cavity B of the smoke tubes. This allows reversal of the flow of smoke without thenecessity of resorting to the use of conventional calandria plates, which naturally simplifies the design of the heat generator. I

Beside having any geometrical cross section, smoke tubes 3' can also be tapered, i.e., can have a varying cross section, as shown in FIGS.. 7 and 8, which can be called for by special design requirements.

By changing the shape of the furnace, and also the shape and the arrangement of the smoke tubes, it is possible to adapt the generator. made in the above-described manner to any kind of liquid, solid or gaseous fuel as well as for functioning for normal combustion or combustion under pressure.

In the design of generators built for combustion under pressure there may be the advantageous possibility of establishing direct communication between the combustion chamber A and smoke channels B as shown in FIGS. 5 and 6.

Actually, in such a case the special seal devices are not required, which, on the other hand, are required in conventional designs. 7

FIGS. 9-and 10 illustrate by way of example two possible embodiments of heat generators, which incorporate a unit of a furnace and smoke tubes, obtained according to the invention.

In FIG. 9, burner 6 is arranged at the top and the furnace is closed at the bottom by a refractory base cover 7, the smoke rising along the inner walls of the furnace, penetrating the smoke tubes B to escape at the bottom, as shown by arrows C.

In the embodiment illustrated in FIG. 10. burner 6 is located at the top and the smoke, going through passageways 5 arranged at the bottom, rises along the smoke tubes B to escape at the top, as shown by arrows C.

In both cases the tube unit is surrounded by a jacket of water 8, 8'.

It is understood that while the basic concept of the invention remains the same, the embodiments thereof and the structural details can be widely vary from d that which has been described and illustrated without departing from the scope of the present invention.

Thus, for example, the burner can be so arranged that the axis of the flame ray may form with the axis of the furnace an angle of any inclination.

I claim 1. In a boiler assembly having an outer jacket and an inner jacket forming a conduit for a fluid to be heated, a combustion chamber located within the inner jacket and a series of exhaust passages for combustion products, each passage extending along the side of the combustion chamber and communicating with it at one of its ends, the improvement comprising a single sheet of metal folded to form the inner jacket, combustion chamber and exhaust passages of the boiler assembly, the combustion chamber having a substantially cylindrical shape with the exhaust passages spaced at intervals around the external periphery of the combustion chamber to form corrugations on the outer surface, the corrugated outer surface forming the inner jacket whereby a one piece unit is provided for a boiler assembly.

2. In a boiler assembly as in claim 1, the exhaust passages being flared radially inward from the periphery of the combustion chamber at one end thereof to provide a fluid communication between the exhaust passages and the combustion chamber.

3. In a boiler assembly as in claim 2, the combustion chamber inner surface being substantially formed of a series of contiguous flat surfaces and the exhaust passages having a substantially triangular configuration.

4. A method of assembling a boiler for heating liquids with hot gases of combustion comprising the steps of providing a single sheet of metal; bending the sheet of metal to fonn a substantially cylindrical combustion chamber and integral serting the bent sheet of metal into an outer housing so that its outer cylindrical surface forms an inner surface of a passageway for liquids to be heated, the passageway being peripheral exhaust passages for conveying the by-products of 5 defined between the outer housmg and the Surface combustion from the cylindrical combustion chamber; and in- I i l I 

1. In a boiler assembly having an outer jacket and an inner jacket forming a conduit for a fluid to be heated, a combustion chamber located within the inner jacket and a series of exhaust passages for combustion products, each passage extending along the side of the combustion chamber and communicating with it at one of its ends, the improvement comprising a single sheet of metal folded to form the inner jacket, combustion chamber and exhaust passages of the boiler assembly, the combustion chamber having a substantially cylindrical shape with the exhaust passages spaced at intervals around the external periphery of the combustion chamber to form corrugations on the outer surface, the corrugated outer surface forming the inner jacket whereby a one piece unit is provided for a boiler assembly.
 2. In a boiler assembly as in claim 1, the exhaust passages being flared radially inward from the periphery of the combustion chamber at one end thereof to provide a fluid communication between the exhaust passages and the combustion chamber.
 3. In a boiler assembly as in claim 2, the combustion chamber inner surface being substantially formed of a series of contiguous flat surfaces and the exhaust passages having a substantially triangular configuration.
 4. A method of assembling a boiler for heating liquids with hot gases of combustion comprising the steps of providing a single sheet of metal; bending the sheet of metal to form a substantially cylindrical combustion chamber and integral peripheral exhaust passages for conveying the by-products of combustion from the cylindrical combustion chamber; and inserting the bent sheet of metal into an outer housing so that its outer cylindrical surface forms an inner surface of a passageway for liquids to be heated, the passageway being defined between the outer housing and the inner surface. 